The present invention broadly relates to munitions and, more specifically, relates to a new and improved construction of a base fuze for a spinning projectile.
Generally speaking, the base fuze of the present invention comprises a detonator capsule or cap and a firing pin for piercing or puncturing the detonator capsule or cap. A hammer sleeve is connected to the firing pin. Furthermore, there is provided an inertia body for increasing the response sensitivity of the base fuze. This inertia body is positioned rearwardly of or behind the hammer sleeve such that upon impact of the projectile at the target the inertia body bears directly against the hammer sleeve in order to increase the effect of the mass of the hammer sleeve during piercing of the detonator capsule or cap by the firing pin owing to the moment of inertia of the inertia body. A fuze housing possesses a bore therein and this bore has an inner wall. The inertia body is axially and radially movable within this bore. The inertia body and/or the inner wall of the bore possess a conical surface which opens or diverges in the direction of flight of the spinning projectile.
In Swiss Patent No. 585,891 and the cognate U.S. Pat. No. 3,995,557, granted Dec. 7, 1976, there is disclosed to the art a base fuze for spinning projectiles. Here, an inertia body is positioned behind a hammer sleeve which, upon impact of the projectile, directly bears against the hammer sleeve. This inertia body possesses two cylindrical sections of different diameter. These two cylindrical sections are interconnected with one another by a forwardly widening or increasing conical surface as seen in the firing direction of the projectile. Another embodiment of this base fuze employs an inertia body which is arranged within a bore of a fuze housing. This bore possesses two cylindrical sections of different diameter which are interconnected with one another by a forwardly widening conical surface as seen in the direction of the flight path or in the firing direction of the projectile.
This known base fuze is provided with a self-destruction spring which effectuates self-destruction of the projectile in the event the projectile fails to strike the target. To ensure that during the self-destruction no large mass need be accelerated in order to pierce or puncture the detonator capsule, the hammer sleeve together with the firing pin is fabricated as lightly as possible. Upon impact of the projectile at the target the firing pin together with the hammer sleeve, however, should be propelled as rapidly as possible against the detonator capsule and, for this reason, the inertia body is constructed as heavy as possible. The conical surface of the inertia body or of the bore in the fuze housing improves the response sensitivity of the fuze when impacting a target at a small or flat angle.
A disadvantage of this prior art base fuze resides in the fact that the required response sensitivity thereof is only ensured when the piercing or puncturing of the detonator capsule by means of the firing pin is augmented by the self-destruction spring.
A further prior art construction of base fuze for a spinning projectile is disclosed in U.S. Pat. No. 4,440,085, granted Apr. 3, 1984.